shaping techniques Flashcards
1
Q
features of milling machines
A
- removes material one thin layer at a time
- machines can be set to a particular cutting speed and depth
- can be used to make a surface absolutely flat and can produce a very accurate finish
2
Q
features of Lathes
A
- come in two types ; wood lathes and engineers lathes
- used to ‘turn’ materials
3
Q
features of 3D printing
A
- additive
- works by printing layers of molten plastic, power or wax until the full 3D shape has been formed
- can design your ideas on screen using various softwares packages
4
Q
what does press forming involve
A
- involves pressing metal sheets between two moulds with a large amount of force
- the metal sheets to be pressed are often annealed, as it makes them more malleable
5
Q
how does press forming work
A
- a sheet of metal is placed between two moulds (a punch and a die)
- a hydraulic press moves the punch down and a large force is applied to the metal sheet
- this pushes the sheet of metal into the die, producing the required shape
6
Q
what does casting involve
A
- molten material being poured into a hollow mould
- material is then left to cook and solidify before being separated from the mould
7
Q
features of die casting
A
- used to mould metals and thermoforming plastics
8
Q
outline the process of die casting
A
- material is melted and poured into a mould that’s the shape of the product
- it’s then allowed to cool. once it’s solidified, it can be removed from the mould
- some plastic resins can be cold poured into moulds and garden through a chemical reaction
- when the products removed, it may need to be trimmed to remove any excess material
9
Q
ways materials can be bent
A
- sheet metal folder - to shape sheet metals such as aluminium and tin
- laminating - to bend wood
- line bending - ideal for use with acrylic
10
Q
outline the process of vacuum forming
A
- a mould is put onto the vacuum bed
- thermoforming plastics are clamped above the vacuum bed and heated until they go soft
- the vacuum bed is lifted close to the heated plastic
- air is sucked out from under the plastic. the air pressure from outside the mould then forces the plastic onto the mould
- the moulded plastic is cooled and the vacuum bed lowered
- the cold plastic is rigid and holds its new shape
11
Q
what does blow moulding involve
A
- a tube of softened plastic is inserted into a solid mould
- air is then injected which forces the plastic to expand to the shape of the mould
- this methods often used to produce bottles and containers
12
Q
features of injection moulding
A
- similar to casting, but the molten material is forced into a closed mould under pressure
- these moulds are often made from tool steel, and the plastic is often melted using built in heaters
- can be used to make things like plastic buckets and watering cans
13
Q
features of extrusion
A
- similar to injection moulding
- used for thermoforming plastics and some metals
- material is melted and forced under pressure through a die
- produces long and continuous strips
- used for products such as plastic covered wire, plastic and aluminium window frames
14
Q
features of drape forming
A
- sheet of thermoforming plastic is heated till it softens
- soften sheets takes the shape of the mould that it’s placed in
- once it’s cooled it will stay that shape
15
Q
examples of glues (adhesives)
A
- polyvinyl acetate (PVA) - used w wood, paper and card, dries slowly
- glue guns - good for modelling, used on woods and fabrics
- solvent cement - used on plastics, needs to be clamped while it sets
- epoxy resin and superglue - used on most materials but expensive
